//
// Box drawing code for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2025 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
//     https://www.fltk.org/bugs.php
//

/**
  \file fl_boxtype.cxx
  \brief Drawing code for common box types.
*/

// Box drawing code for the common box types and the table of
// boxtypes.  Other box types are in separate files so they are not
// linked in if not used.

#include "src/Fl_Private.H"
#include <FL/Fl_Widget.H>
#include <FL/fl_draw.H>
#include <config.h>

////////////////////////////////////////////////////////////////

static const uchar active_ramp[24] = {
  FL_GRAY_RAMP+0, FL_GRAY_RAMP+1, FL_GRAY_RAMP+2, FL_GRAY_RAMP+3,
  FL_GRAY_RAMP+4, FL_GRAY_RAMP+5, FL_GRAY_RAMP+6, FL_GRAY_RAMP+7,
  FL_GRAY_RAMP+8, FL_GRAY_RAMP+9, FL_GRAY_RAMP+10,FL_GRAY_RAMP+11,
  FL_GRAY_RAMP+12,FL_GRAY_RAMP+13,FL_GRAY_RAMP+14,FL_GRAY_RAMP+15,
  FL_GRAY_RAMP+16,FL_GRAY_RAMP+17,FL_GRAY_RAMP+18,FL_GRAY_RAMP+19,
  FL_GRAY_RAMP+20,FL_GRAY_RAMP+21,FL_GRAY_RAMP+22,FL_GRAY_RAMP+23};
static const uchar inactive_ramp[24] = {
  43, 43, 44, 44,
  44, 45, 45, 46,
  46, 46, 47, 47,
  48, 48, 48, 49,
  49, 49, 50, 50,
  51, 51, 52, 52};
static int draw_it_active = 1;

int Fl::Private::box_border_radius_max_ = 15;

/** Get the maximum border radius of all "rounded" boxtypes in pixels.
    \since 1.4.0
*/
int Fl::box_border_radius_max() {
  return Private::box_border_radius_max_;
}

/** Set the maximum border radius of all "rounded" boxtypes in pixels.
  Must be at least 5, default = 15.

  \note This does \b not apply to the "round" boxtypes which have really round sides
    (i.e. composed of half circles) as opposed to "rounded" boxtypes that have only
    rounded corners with a straight border between corners.

  The box border radius of "rounded" boxtypes is typically calculated as about 2/5 of
  the box height or width, whichever is smaller. The upper limit can be set by this
  method for all "rounded" boxtypes.
  \since 1.4.0
*/
void Fl::box_border_radius_max(int R) {
  Private::box_border_radius_max_ = R < 5 ? 5 : R;
}

int Fl::Private::box_shadow_width_ = 3;

/** Get the box shadow width of all "shadow" boxtypes in pixels.
  \since 1.4.0
*/
int Fl::box_shadow_width() {
  return Private::box_shadow_width_;
}

/** Set the box shadow width of all "shadow" boxtypes in pixels.
  Must be at least 1, default = 3. There is no upper limit.
  \since 1.4.0
*/
void Fl::box_shadow_width(int W) {
  Private::box_shadow_width_ = W < 1 ? 1 : W;
}

/**
  Determines if the currently drawn box is active or inactive.

  If inactive, the box color should be changed to the inactive color.

  \see Fl::box_color(Fl_Color c)
*/
int Fl::draw_box_active() { return draw_it_active; }

// Note: the pointer that is returned by this function works only with indexes
//       between 65 ('A') and including 88 ('X').
const uchar *fl_gray_ramp() {return (static_cast<const uchar*>(draw_it_active?active_ramp:inactive_ramp))-'A';}

/**
  Gets the drawing color to be used for the background of a box.

  This method is only useful inside box drawing code. It returns the
  color to be used, either fl_inactive(c) if the widget is !active_r()
  or \p c otherwise.
*/
Fl_Color Fl::box_color(Fl_Color c) {
  return (draw_it_active ? c : fl_inactive(c));
}

/**
  Sets the drawing color for the box that is currently drawn.

  This method sets the current drawing color fl_color() depending on
  the widget's state to either \p c or fl_inactive(c).

  It should be used whenever a box background is drawn in the box (type)
  drawing code instead of calling fl_color(Fl_Color bg) with the
  background color \p bg, usually Fl_Widget::color().

  This method is only useful inside box drawing code. Whenever a box is
  drawn with one of the standard box drawing methods, a static variable
  is set depending on the widget's current state - if the widget is
  !active_r() then the internal variable is false (0), otherwise it
  is true (1). This is faster than calling Fl_Widget::active_r()
  because the state is cached.

  \see Fl::draw_box_active()
  \see Fl::box_color(Fl_Color)
*/
void Fl::set_box_color(Fl_Color c) { fl_color(box_color(c)); }

/**
  Draws a series of line segments around the given box.
  The string \p s must contain groups of 4 letters which specify one of 24
  standard grayscale values, where 'A' is black and 'X' is white.
  The order of each set of 4 characters is: top, left, bottom, right.
  The result of calling fl_frame() with a string that is not a multiple
  of 4 characters in length is undefined.
  The only difference between this function and fl_frame2() is the order
  of the line segments.
  \param[in] s sets of 4 grayscale values in top, left, bottom, right order
  \param[in] x, y, w, h position and size
*/
void fl_frame(const char* s, int x, int y, int w, int h) {
  const uchar *g = fl_gray_ramp();
  if (h > 0 && w > 0) for (;*s;) {
    // draw top line:
    fl_color(g[(int)*s++]);
    fl_xyline(x, y, x+w-1);
    y++; if (--h <= 0) break;
    // draw left line:
    fl_color(g[(int)*s++]);
    fl_yxline(x, y+h-1, y);
    x++; if (--w <= 0) break;
    // draw bottom line:
    fl_color(g[(int)*s++]);
    fl_xyline(x, y+h-1, x+w-1);
    if (--h <= 0) break;
    // draw right line:
    fl_color(g[(int)*s++]);
    fl_yxline(x+w-1, y+h-1, y);
    if (--w <= 0) break;
  }
}

/**
  Draws a series of line segments around the given box.
  The string \p s must contain groups of 4 letters which specify one of 24
  standard grayscale values, where 'A' is black and 'X' is white.
  The order of each set of 4 characters is: bottom, right, top, left.
  The result of calling fl_frame2() with a string that is not a multiple
  of 4 characters in length is undefined.
  The only difference between this function and fl_frame() is the order
  of the line segments.
  \param[in] s sets of 4 grayscale values in bottom, right, top, left order
  \param[in] x, y, w, h position and size
*/
void fl_frame2(const char* s, int x, int y, int w, int h) {
  const uchar *g = fl_gray_ramp();
  if (h > 0 && w > 0) for (;*s;) {
    // draw bottom line:
    fl_color(g[(int)*s++]);
    fl_xyline(x, y+h-1, x+w-1);
    if (--h <= 0) break;
    // draw right line:
    fl_color(g[(int)*s++]);
    fl_yxline(x+w-1, y+h-1, y);
    if (--w <= 0) break;
    // draw top line:
    fl_color(g[(int)*s++]);
    fl_xyline(x, y, x+w-1);
    y++; if (--h <= 0) break;
    // draw left line:
    fl_color(g[(int)*s++]);
    fl_yxline(x, y+h-1, y);
    x++; if (--w <= 0) break;
  }
}

/** Draws a box of type FL_NO_BOX */
void fl_no_box(int, int, int, int, Fl_Color) {}

/** Draws a box of type FL_FLAT_BOX */
void fl_flat_box(int x, int y, int w, int h, Fl_Color c) {
  fl_rectf(x, y, w, h, Fl::box_color(c));
}

/** Draws a frame of type FL_THIN_DOWN_FRAME */
void fl_thin_down_frame(int x, int y, int w, int h, Fl_Color) {
  fl_frame2("WWHH",x,y,w,h);
}

/** Draws a box of type FL_THIN_DOWN_BOX */
void fl_thin_down_box(int x, int y, int w, int h, Fl_Color c) {
  fl_thin_down_frame(x,y,w,h,c);
  Fl::set_box_color(c);
  fl_rectf(x+1, y+1, w-2, h-2);
}

/** Draws a frame of type FL_THIN_UP_FRAME */
void fl_thin_up_frame(int x, int y, int w, int h, Fl_Color) {
  fl_frame2("HHWW",x,y,w,h);
}

/** Draws a box of type FL_THIN_UP_BOX */
void fl_thin_up_box(int x, int y, int w, int h, Fl_Color c) {
  fl_thin_up_frame(x,y,w,h,c);
  Fl::set_box_color(c);
  fl_rectf(x+1, y+1, w-2, h-2);
}

/** Draws a frame of type FL_UP_FRAME */
void fl_up_frame(int x, int y, int w, int h, Fl_Color) {
#if BORDER_WIDTH == 1
  fl_frame2("HHWW",x,y,w,h);
#else
#if BORDER_WIDTH == 2
  fl_frame2("AAWWMMTT",x,y,w,h);
#else
  fl_frame("AAAAWWJJUTNN",x,y,w,h);
#endif
#endif
}

#define D1 BORDER_WIDTH
#define D2 (BORDER_WIDTH+BORDER_WIDTH)

/** Draws a box of type FL_UP_BOX */
void fl_up_box(int x, int y, int w, int h, Fl_Color c) {
  fl_up_frame(x,y,w,h,c);
  Fl::set_box_color(c);
  fl_rectf(x+D1, y+D1, w-D2, h-D2);
}

/** Draws a frame of type FL_DOWN_FRAME */
void fl_down_frame(int x, int y, int w, int h, Fl_Color) {
#if BORDER_WIDTH == 1
  fl_frame2("WWHH",x,y,w,h);
#else
#if BORDER_WIDTH == 2
  fl_frame2("WWMMPPAA",x,y,w,h);
#else
  fl_frame("NNTUJJWWAAAA",x,y,w,h);
#endif
#endif
}

/** Draws a box of type FL_DOWN_BOX */
void fl_down_box(int x, int y, int w, int h, Fl_Color c) {
  fl_down_frame(x,y,w,h,c);
  Fl::set_box_color(c);
  fl_rectf(x+D1, y+D1, w-D2, h-D2);
}

/** Draws a frame of type FL_ENGRAVED_FRAME */
void fl_engraved_frame(int x, int y, int w, int h, Fl_Color) {
  fl_frame("HHWWWWHH",x,y,w,h);
}

/** Draws a box of type FL_ENGRAVED_BOX */
void fl_engraved_box(int x, int y, int w, int h, Fl_Color c) {
  fl_engraved_frame(x,y,w,h,c);
  Fl::set_box_color(c);
  fl_rectf(x+2, y+2, w-4, h-4);
}

/** Draws a frame of type FL_EMBOSSED_FRAME */
void fl_embossed_frame(int x, int y, int w, int h, Fl_Color) {
  fl_frame("WWHHHHWW",x,y,w,h);
}

/** Draws a box of type FL_EMBOSSED_BOX */
void fl_embossed_box(int x, int y, int w, int h, Fl_Color c) {
  fl_embossed_frame(x,y,w,h,c);
  Fl::set_box_color(c);
  fl_rectf(x+2, y+2, w-4, h-4);
}

/**
  Draws a bounded rectangle with a given position, size and color.
  Equivalent to drawing a box of type FL_BORDER_BOX.
*/
void fl_rectbound(int x, int y, int w, int h, Fl_Color bgcolor) {
  // New algorithm (see Discussion #1089):
  // 1) draw with adequate bg color a filled rectangle that covers also the rectangle border
  // 2) draw with adequate border color the rectangle border overwriting what was drawn at 1)
  Fl::set_box_color(bgcolor);
  fl_rectf(x, y, w, h);
  Fl::set_box_color(FL_BLACK);
  fl_rect(x, y, w, h);
}
#define fl_border_box fl_rectbound      /**< allow consistent naming */

/**
  Draws a frame of type FL_BORDER_FRAME.
*/
void fl_border_frame(int x, int y, int w, int h, Fl_Color c) {
  Fl::set_box_color(c);
  fl_rect(x, y, w, h);
}

void fl_rounded_focus(Fl_Boxtype bt, int x, int y, int w, int h, Fl_Color fg, Fl_Color bg);
void fl_round_focus(Fl_Boxtype, int, int, int, int, Fl_Color, Fl_Color);
void fl_diamond_focus(Fl_Boxtype, int, int, int, int, Fl_Color, Fl_Color);

void fl_shadow_frame(int x, int y, int w, int h, Fl_Color c);
void fl_shadow_box(int x, int y, int w, int h, Fl_Color c);
void fl_rounded_box(int x, int y, int w, int h, Fl_Color c);
void fl_rshadow_box(int x, int y, int w, int h, Fl_Color c);
void fl_rounded_frame(int x, int y, int w, int h, Fl_Color c);
void fl_rflat_box(int x, int y, int w, int h, Fl_Color c);
void fl_round_up_box(int x, int y, int w, int h, Fl_Color bgcolor);
void fl_round_down_box(int x, int y, int w, int h, Fl_Color bgcolor);
void fl_diamond_up_box(int x,int y,int w,int h,Fl_Color bgcolor);
void fl_diamond_down_box(int x,int y,int w,int h,Fl_Color bgcolor);
void fl_oval_focus(Fl_Boxtype bt, int x, int y, int w, int h, Fl_Color fg, Fl_Color bg);
void fl_oval_shadow_box(int x, int y, int w, int h, Fl_Color c);
void fl_oval_box(int x, int y, int w, int h, Fl_Color c);
void fl_oval_frame(int x, int y, int w, int h, Fl_Color c);
void fl_oval_flat_box(int x, int y, int w, int h, Fl_Color c);
void fl_plastic_up_box(int x, int y, int w, int h, Fl_Color c);
void fl_plastic_up_round(int x, int y, int w, int h, Fl_Color c);
void fl_plastic_down_frame(int x, int y, int w, int h, Fl_Color c);
void fl_plastic_down_box(int x, int y, int w, int h, Fl_Color c);
void fl_plastic_down_round(int x, int y, int w, int h, Fl_Color c);
void fl_plastic_up_frame(int x, int y, int w, int h, Fl_Color c);
void fl_plastic_thin_up_box(int x, int y, int w, int h, Fl_Color c);
void fl_gtk_up_frame(int x, int y, int w, int h, Fl_Color c);
void fl_gtk_up_box(int x, int y, int w, int h, Fl_Color c);
void fl_gtk_down_frame(int x, int y, int w, int h, Fl_Color c);
void fl_gtk_down_box(int x, int y, int w, int h, Fl_Color c);
void fl_gtk_thin_up_frame(int x, int y, int w, int h, Fl_Color c);
void fl_gtk_thin_up_box(int x, int y, int w, int h, Fl_Color c);
void fl_gtk_thin_down_frame(int x, int y, int w, int h, Fl_Color c);
void fl_gtk_thin_down_box(int x, int y, int w, int h, Fl_Color c);
void fl_gtk_round_up_box(int x, int y, int w, int h, Fl_Color c);
void fl_gtk_round_down_box(int x, int y, int w, int h, Fl_Color c);
void fl_gleam_up_frame(int x, int y, int w, int h, Fl_Color c);
void fl_gleam_up_box(int x, int y, int w, int h, Fl_Color c);
void fl_gleam_thin_up_box(int x, int y, int w, int h, Fl_Color c);
void fl_gleam_down_frame(int x, int y, int w, int h, Fl_Color c);
void fl_gleam_down_box(int x, int y, int w, int h, Fl_Color c);
void fl_gleam_thin_down_box(int x, int y, int w, int h, Fl_Color c);
void fl_oxy_button_up_box(int x, int y, int w, int h, Fl_Color col);
void fl_oxy_button_down_box(int x, int y, int w, int h, Fl_Color col);
void fl_oxy_up_box(int x, int y, int w, int h, Fl_Color col);
void fl_oxy_down_box(int x, int y, int w, int h, Fl_Color col);
void fl_oxy_thin_up_box(int x, int y, int w, int h, Fl_Color col);
void fl_oxy_thin_down_box(int x, int y, int w, int h, Fl_Color col);
void fl_oxy_up_frame(int x, int y, int w, int h, Fl_Color col);
void fl_oxy_down_frame(int x, int y, int w, int h, Fl_Color col);
void fl_oxy_thin_up_frame(int x, int y, int w, int h, Fl_Color col);
void fl_oxy_thin_down_frame(int x, int y, int w, int h, Fl_Color col);
void fl_oxy_round_up_box(int x, int y, int w, int h, Fl_Color col);
void fl_oxy_round_down_box(int x, int y, int w, int h, Fl_Color col);


// /////////////////////////////////////////////////////////////////////
// Up to FLTK 1.4 the 6th element of the following struct was named 'set'
// and could only be 0 or 1: whether the boxtype was "set" or not.
// Since FLTK 1.5 the 6th element of the struct is named 'flags' and
// is used as a set of bit flags:
// - bit 0 (1): 1 = set, 0 = not (yet) set (fully initialized)
// - bit 1 (2): 0 = boxtype has a solid background, 1 = no (frame type)
// - bit 3 ++ : undefined, must be 0, reserved for future extensions.
// The bit values were chosen so the default is suitable for backwards
// compatibility, i.e. if users defining their own schemes don't set the
// corresponding bits.
// To do: define an enum for bit values ?
// To do: check if "diamond" and "oval" boxes need bit 1 == 1 like frames.
// See also Fl::box_bg() which returns true if bit 1 == zero.
// /////////////////////////////////////////////////////////////////////

typedef struct {
  Fl_Box_Draw_F *f;
  uchar dx, dy, dw, dh;
  int flags;
  Fl_Box_Draw_Focus_F *ff;
  bool set() { return flags & 1; }
  bool bg()  { return !(flags & 2); }
} boxtable_t;

static boxtable_t fl_box_table[FL_MAX_BOXTYPE+1] = {

  // must match list in Enumerations.H !!!
  { fl_no_box,              0, 0, 0, 0,  3 },   // FL_NO_BOX
  { fl_flat_box,            0, 0, 0, 0,  1 },   // FL_FLAT_BOX
  { fl_up_box,              D1, D1, D2, D2,  1 },  // FL_UP_BOX
  { fl_down_box,            D1, D1, D2, D2,  1 },  // FL_DOWN_BOX
  { fl_up_frame,            D1, D1, D2, D2,  3 },  // FL_UP_FRAME
  { fl_down_frame,          D1, D1, D2, D2,  3 },  // FL_DOWN_FRAME
  { fl_thin_up_box,         1, 1, 2, 2,  1 },   // FL_THIN_UP_BOX
  { fl_thin_down_box,       1, 1, 2, 2,  1 },   // FL_THIN_DOWN_BOX,
  { fl_thin_up_frame,       1, 1, 2, 2,  3 },   // FL_THIN_UP_FRAME,
  { fl_thin_down_frame,     1, 1, 2, 2,  3 },   // FL_THIN_DOWN_FRAME,
  { fl_engraved_box,        2, 2, 4, 4,  1 },   // FL_ENGRAVED_BOX,
  { fl_embossed_box,        2, 2, 4, 4,  1 },   // FL_EMBOSSED_BOX,
  { fl_engraved_frame,      2, 2, 4, 4,  3 },   // FL_ENGRAVED_FRAME
  { fl_embossed_frame,      2, 2, 4, 4,  3 },   // FL_EMBOSSED_FRAME
  { fl_border_box,          1, 1, 2, 2,  1 },   // FL_BORDER_BOX
  { fl_shadow_box,          1, 1, 5, 5,  1 },   // FL_SHADOW_BOX
  { fl_border_frame,        1, 1, 2, 2,  3 },   // FL_BORDER_FRAME,
  { fl_shadow_frame,        1, 1, 5, 5,  3 },   // FL_SHADOW_FRAME
  { fl_rounded_box,         1, 1, 2, 2,  1, fl_rounded_focus },   // FL_ROUNDED_BOX
  { fl_rshadow_box,         1, 1, 2, 2,  1, fl_rounded_focus },   // FL_RSHADOW_BOX
  { fl_rounded_frame,       1, 1, 2, 2,  3, fl_rounded_focus },   // FL_ROUNDED_FRAME
  { fl_rflat_box,           0, 0, 0, 0,  1, fl_rounded_focus },   // FL_RFLAT_BOX
  { fl_round_up_box,        3, 3, 6, 6,  1, fl_round_focus },     // FL_ROUND_UP_BOX
  { fl_round_down_box,      3, 3, 6, 6,  1, fl_round_focus },     // FL_ROUND_DOWN_BOX
  { fl_diamond_up_box,      0, 0, 0, 0,  1, fl_diamond_focus },   // FL_DIAMOND_UP_BOX
  { fl_diamond_down_box,    0, 0, 0, 0,  1, fl_diamond_focus },   // FL_DIAMOND_DOWN_BOX
  { fl_oval_box,            1, 1, 2, 2,  1, fl_oval_focus },      // FL_OVAL_BOX
  { fl_oval_shadow_box,     1, 1, 2, 2,  1, fl_oval_focus },      // FL_OSHADOW_BOX
  { fl_oval_frame,          1, 1, 2, 2,  2, fl_oval_focus },      // FL_OVAL_FRAME
  { fl_oval_flat_box,       0, 0, 0, 0,  1, fl_oval_focus },      // FL_OFLAT_BOX
  { fl_plastic_up_box,      2, 2, 4, 4,  1 },   // _FL_PLASTIC_UP_BOX
  { fl_plastic_down_box,    2, 2, 4, 4,  1 },   // _FL_PLASTIC_DOWN_BOX
  { fl_plastic_up_frame,    2, 2, 4, 4,  3 },   // _FL_PLASTIC_UP_FRAME
  { fl_plastic_down_frame,  2, 2, 4, 4,  3 },   // _FL_PLASTIC_DOWN_FRAME
  { fl_plastic_thin_up_box, 2, 2, 4, 4,  1 },   // _FL_PLASTIC_THIN_UP_BOX
  { fl_plastic_down_box,    2, 2, 4, 4,  1 },   // _FL_PLASTIC_THIN_DOWN_BOX
  { fl_plastic_up_round,    2, 2, 4, 4,  1, fl_round_focus },     // _FL_PLASTIC_ROUND_UP_BOX
  { fl_plastic_down_round,  2, 2, 4, 4,  1, fl_round_focus },     // _FL_PLASTIC_ROUND_DOWN_BOX
  { fl_gtk_up_box,          2, 2, 4, 4,  1 },   // _FL_GTK_UP_BOX
  { fl_gtk_down_box,        2, 2, 4, 4,  1 },   // _FL_GTK_DOWN_BOX
  { fl_gtk_up_frame,        2, 2, 4, 4,  3 },   // _FL_GTK_UP_FRAME
  { fl_gtk_down_frame,      2, 2, 4, 4,  3 },   // _FL_GTK_DOWN_FRAME
  { fl_gtk_thin_up_box,     1, 1, 2, 2,  3 },   // FL_GTK_THIN_UP_BOX
  { fl_gtk_thin_down_box,   1, 1, 2, 2,  3 },   // FL_GTK_THIN_DOWN_BOX
  { fl_gtk_thin_up_frame,   1, 1, 2, 2,  1 },   // FL_GTK_THIN_UP_FRAME
  { fl_gtk_thin_down_frame, 1, 1, 2, 2,  1 },   // FL_GTK_THIN_DOWN_FRAME
  { fl_gtk_round_up_box,    2, 2, 4, 4,  1, fl_round_focus },     // FL_GTK_ROUND_UP_BOX
  { fl_gtk_round_down_box,  2, 2, 4, 4,  1, fl_round_focus },     // FL_GTK_ROUND_DOWN_BOX
  { fl_gleam_up_box,        2, 2, 4, 4,  1 },   // _FL_GLEAM_UP_BOX
  { fl_gleam_down_box,      2, 2, 4, 4,  1 },   // _FL_GLEAM_DOWN_BOX
  { fl_gleam_up_frame,      2, 2, 4, 4,  3 },   // _FL_GLEAM_UP_FRAME
  { fl_gleam_down_frame,    2, 2, 4, 4,  3 },   // _FL_GLEAM_DOWN_FRAME
  { fl_gleam_thin_up_box,   2, 2, 4, 4,  1 },   // _FL_GLEAM_THIN_UP_BOX
  { fl_gleam_thin_down_box, 2, 2, 4, 4,  1 },   // _FL_GLEAM_THIN_DOWN_BOX
  { fl_gleam_up_box,        2, 2, 4, 4,  1 },   // _FL_GLEAM_ROUND_UP_BOX
  { fl_gleam_down_box,      2, 2, 4, 4,  1 },   // _FL_GLEAM_ROUND_DOWN_BOX
  { fl_oxy_up_box,          2, 2, 4, 4,  1 },   // _FL_OXY_UP_BOX,
  { fl_oxy_down_box,        2, 2, 4, 4,  1 },   // _FL_OXY_DOWN_BOX,
  { fl_oxy_up_frame,        2, 2, 4, 4,  3 },   // _FL_OXY_UP_FRAME,
  { fl_oxy_down_frame,      2, 2, 4, 4,  3 },   // _FL_OXY_DOWN_FRAME,
  { fl_oxy_thin_up_box,     1, 1, 2, 2,  1 },   // _FL_OXY_THIN_UP_BOX,
  { fl_oxy_thin_down_box,   1, 1, 2, 2,  1 },   // _FL_OXY_THIN_DOWN_BOX,
  { fl_oxy_thin_up_frame,   1, 1, 2, 2,  3 },   // _FL_OXY_THIN_UP_FRAME,
  { fl_oxy_thin_down_frame, 1, 1, 2, 2,  3 },   // _FL_OXY_THIN_DOWN_FRAME,
  { fl_oxy_round_up_box,    2, 2, 4, 4,  1, fl_round_focus },     // _FL_OXY_ROUND_UP_BOX,
  { fl_oxy_round_down_box,  2, 2, 4, 4,  1, fl_round_focus },     // _FL_OXY_ROUND_DOWN_BOX,
  { fl_oxy_button_up_box,   2, 2, 4, 4,  1 },   // _FL_OXY_BUTTON_UP_BOX,
  { fl_oxy_button_down_box, 2, 2, 4, 4,  1 },   // _FL_OXY_BUTTON_DOWN_BOX,
  { fl_up_box,              3, 3, 6, 6,  1 },   // FL_FREE_BOX+0
  { fl_down_box,            3, 3, 6, 6,  1 },   // FL_FREE_BOX+1
  { fl_up_box,              3, 3, 6, 6,  1 },   // FL_FREE_BOX+2
  { fl_down_box,            3, 3, 6, 6,  1 },   // FL_FREE_BOX+3
  { fl_up_box,              3, 3, 6, 6,  1 },   // FL_FREE_BOX+4
  { fl_down_box,            3, 3, 6, 6,  1 },   // FL_FREE_BOX+5
  { fl_up_box,              3, 3, 6, 6,  1 },   // FL_FREE_BOX+6
  { fl_down_box,            3, 3, 6, 6,  1 }    // FL_FREE_BOX+7
};

/**
  Returns the X offset for the given boxtype.
  \see box_dy()
*/
int Fl::box_dx(Fl_Boxtype t) {return fl_box_table[t].dx;}

/**
    Returns the Y offset for the given boxtype.

    These functions return the offset values necessary for a given
    boxtype, useful for computing the area inside a box's borders, to
    prevent overdrawing the borders.

    For instance, in the case of a boxtype like FL_DOWN_BOX
    where the border width might be 2 pixels all around, the above
    functions would return 2, 2, 4, and 4 for box_dx,
    box_dy, box_dw, and box_dh respectively.

    An example to compute the area inside a widget's box():
    \code
         int X = yourwidget->x() + Fl::box_dx(yourwidget->box());
         int Y = yourwidget->y() + Fl::box_dy(yourwidget->box());
         int W = yourwidget->w() - Fl::box_dw(yourwidget->box());
         int H = yourwidget->h() - Fl::box_dh(yourwidget->box());
    \endcode
    These functions are mainly useful in the draw() code
    for deriving custom widgets, where one wants to avoid drawing
    over the widget's own border box().
*/
int Fl::box_dy(Fl_Boxtype t) {return fl_box_table[t].dy;}

/**
  Returns the width offset for the given boxtype.
  \see box_dy().
*/
int Fl::box_dw(Fl_Boxtype t) {return fl_box_table[t].dw;}

/**
  Returns the height offset for the given boxtype.
  \see box_dy().
*/
int Fl::box_dh(Fl_Boxtype t) {return fl_box_table[t].dh;}

/**
  Returns whether the given boxtype draws its background.

  FL_NO_BOX and all FL_*_FRAME boxtypes need their parent to draw the
  background rather than just calling redraw. This is used internally
  for some widgets to ensure that the background is fully drawn when,
  for instance, only the focus box is changed.

  \param[in]  bt  Boxtype
  \return     true if the box draws a solid background,\n
              false if it is at least partially transparent.
  \since 1.5.0
*/
extern bool Fl::box_bg(Fl_Boxtype bt) {
  return fl_box_table[bt].bg();
}

/*
 Starting with FLTK version 1.5, this is no longer needed. Use Fl::set_boxtype().
 void fl_internal_boxtype(Fl_Boxtype t, Fl_Box_Draw_F* f, Fl_Box_Draw_Focus_F* ff)
 */

/** Gets the current box drawing function for the specified box type. */
Fl_Box_Draw_F *Fl::get_boxtype(Fl_Boxtype t) {
  return fl_box_table[t].f;
}

/**
 Sets the function to call to draw a specific box type.

 \param[in] t  index of the box type between 0 (FL_NO_BOX) and up to and
 including FL_MAX_BOXTYPE
 \param[in] f  callback function that draws the box
 \param[in] dx, dy top left frame width, distance in pixels to box contents
 \param[in] dw, dh left plus right frame width, top plus bottom frame width
 \param[in] ff optional callback that draws the box focus, defaults
 to a rectangle, inset by dx, dy, dw, dh
 */
void Fl::set_boxtype(Fl_Boxtype t, Fl_Box_Draw_F* f,
                     uchar dx, uchar dy, uchar dw, uchar dh,
                     Fl_Box_Draw_Focus_F* ff) {
  fl_box_table[t].f      = f;
  fl_box_table[t].flags |= 1;
  fl_box_table[t].dx     = dx;
  fl_box_table[t].dy     = dy;
  fl_box_table[t].dw     = dw;
  fl_box_table[t].dh     = dh;
  fl_box_table[t].ff     = ff;
}

/** Copies the from boxtype. */
void Fl::set_boxtype(Fl_Boxtype to, Fl_Boxtype from) {
  fl_box_table[to] = fl_box_table[from];
}

/**
  Draws a box using given type, position, size and color.
  \param[in] t box type
  \param[in] x, y, w, h position and size
  \param[in] c color
*/
void fl_draw_box(Fl_Boxtype t, int x, int y, int w, int h, Fl_Color c) {
  if (t && fl_box_table[t].f) fl_box_table[t].f(x,y,w,h,c);
}

/**
 Draws the focus rectangle inside a box using given type, position, size and color.
 Boxes can set their own focus drawing callback. The focus frame does not
 need to be a rectangle at all, but should fit inside the shape of the box.
 \param[in] bt box type
 \param[in] x, y, w, h position and size
 \param[in] fg, bg foreground and background color
 */
void fl_draw_box_focus(Fl_Boxtype bt, int x, int y, int w, int h, Fl_Color fg, Fl_Color bg) {
  if (!Fl::visible_focus()) return;
  if ((bt >= 0) && (bt <= FL_MAX_BOXTYPE) && (fl_box_table[bt].ff)) {
    fl_box_table[bt].ff(bt, x, y, w, h, fg, bg);
    return;
  }
  switch (bt) {
    case FL_DOWN_BOX:
    case FL_DOWN_FRAME:
    case FL_THIN_DOWN_BOX:
    case FL_THIN_DOWN_FRAME:
      x++;
      y++;
    default:
      break;
  }
  x += Fl::box_dx(bt);
  y += Fl::box_dy(bt);
  w -= Fl::box_dw(bt)+1;
  h -= Fl::box_dh(bt)+1;

  Fl_Color savecolor = fl_color();
  fl_color(fl_contrast(fg, bg));
  fl_focus_rect(x, y, w, h);
  fl_color(savecolor);
}

/** Draws the widget box according to its box style */
void Fl_Widget::draw_box() const {
  if (box_) draw_box((Fl_Boxtype)box_, x_, y_, w_, h_, color_);
  draw_backdrop();
}
/** If FL_ALIGN_IMAGE_BACKDROP is set, the image or deimage will be drawn */
void Fl_Widget::draw_backdrop() const {
  if (align() & FL_ALIGN_IMAGE_BACKDROP) {
    const Fl_Image *img = image();
    // if there is no image, we will not draw the deimage either
    if (img && deimage() && !active_r())
      img = deimage();
    if (img)
      ((Fl_Image*)img)->draw(x_+(w_-img->w())/2, y_+(h_-img->h())/2);
  }
}
/** Draws a box of type t, of color c at the widget's position and size. */
void Fl_Widget::draw_box(Fl_Boxtype t, Fl_Color c) const {
  draw_box(t, x_, y_, w_, h_, c);
}
/** Draws a box of type t, of color c at the position X,Y and size W,H. */
void Fl_Widget::draw_box(Fl_Boxtype t, int X, int Y, int W, int H, Fl_Color c) const {
  draw_it_active = active_r();
  fl_box_table[t].f(X, Y, W, H, c);
  draw_it_active = 1;
}
